Apparatus for burning liquid fuel



Dec. l5; 1936. M. A. POWERS APPARATUS FOR BURNING LIQUID FUEL FiledSept. 20,1934 3 Sheets-Sheet l IU/ s w Tm 3A n 0 W 6W 6M w 6 s A 0 6 Zv\\\\\\\\\\\\\\w\\\ M *0 C m l il! ml I l m llll A. ,u f o Dec. 15,193e. M A POWERS 2,064,080

APPARATUS FOR BURNING LIQUID FUEL Filed Sept. 20, 1934 5 Sheets-Sheet 2lll/[All 111/ f ai @o /f /aa o I I o INVENTOR M/zan A. Powe/1r Dec. 15,1936. vM. A. POWERS 2,064,080

APPARATUS FOR BURNING LIQUID FUEL .E- gli INVENTOR //Vfo/z A. Powe/v 0www #www ATTORNEYS' Patented Dec. 15, 1936 UNITED STATES PATENT OFFICE:A

Timken-Silent Automatic Company,

Mich., a corporation Application September 3 Claims.

The present invention relates to apparatus for burning liquid fuel. Moreparticularly my invention is concerned with apparatus for heating waterby means of liquid fuel.

My invention intends to provide a boiler and oil burner assembly capable.of unusually high efficiency in operation as a consequence of. theparticular relations, features of design and construction of the heatproducing and heating exchanging or absorbing elements. It is a wellknown fact that boilers specially designed for use with oil burners arecapable of operating at increased eiciencies over those into which theordinary conversion type oil burner may be installed. This isconventionally accomplished by increasing the heat absorbing areas overwhich the hot gases are passed after leaving the combustion chamber.With my improved construe#` tion a greatly increased proportion ofthetotal heat absorbed comes directly from the combustion chamber,resulting in a marked increase in efliciency, and greater output from aboiler of smaller dimensions. The use of a metallic hearth and a novelmethod of mounting the oil burner in the boiler assists greatly inproducing these desired results.

In order to properly understand the functioning of my design it may bewell todiscuss briefly the results ordinarily obtained by installingvarious types of oil burners in the conventional home heating boilers.Most heating boilers are designed for burning solid fuel, such as coaland the like, and when they are transformed into oil burning units, theshort flue travel which has previously been satisfactory with theslowermoving gases resulting from coal combustion is unable to absorb suicientheat generated to provide economical operation. The usual remedy is toincrease the ue length and area, by the addition of extra boilersections, thus giving the hot flue gases a better opportunity to coolbefore leaving the boiler. With the present increasing' demand most ofthe important boiler companies have announced the production of socalled oil burning boilers, particularly suited for eflicientlyabsorbing heat from oil combustion. Examination of the design of suchboilers shows further attempts to build boilers with much elongated fluetravela continuation in effect of the old field practice of adding fluesections to ineici-ent installations, in an effort to improve theiroperation.

It is only natural and logical for this to be the case, particularly asthe resultant boiler may be called upon to operate with any one ofseveral Detroit, of Michigan 20, 1934, Serial No. 744,833

types of burners, each type having a dliferent flame shape and varyingCombustion chamber requirement. Hence any major change in the combustionchamber itself would not be practical, as some of the various burnerslikely to be used with the boiler would be seriously handicapped andothers might be impossible to operate at all. For example, a largeincrease in the heating surface presented to the hot gases in the spacenormally occupied by free combustion chamber gases, so restricts thespace otherwise available as to make it quite impossible to install manytypes ofv oil burners. A gun type domestic burner with its cone shapedflame could not operate effectively with the flame impinging at the backand top against projecting Water-backed portions. Carbon would be boundto collect interfering with combustion and themetal boiler partssubjected to the intense heat of flame impingement would deterioraterapidly'. Likewise a wall flame burner in an extremely long and narrowboiler with corrugated Walls would prove inefficient while a gun typeunit under the same circumstances might give fairly reasonablesatisfaction. However it will be seen, as my inven tion is explained,that the integral design I have produced has inherent advantages andproduces results far beyond thatv possible by any combination ofconventional boiler and burner.

It is a major object of my invention to devise novel liquid-fuel-heatedboilers that will operate with an extremely high degree of eliiciency,and yet which are of small dimensions and cheap of manufacture.

A further important object of the present invention is to deviseliquid-fuel-heated boilers which are so constructedl that substantiallyal1 of the heat transmitted to the water is derived from the combustionchamber itself.

It is another object of my invention to provide a liquid fuel burner ofthe Wall flame type with a Water-cooled hearth; for the purpose ofassisting in segregating the air flow from the fuel flow and therebyinsuring improved combustion conditions.

It is another object of the present invention to devise a boilerespecially designed for use with liquid fuel burners of the wall flametype which Vis so constructed as to present a maximum of water-backedheat-transmitting surface to the combustion region, and tovtherebysubstantially completely envelop the latter.

It is a further object of my invention to devise a boiler having asmooth heat transmitting surface in the region of the burning flame, and

a greatly increased area of heat transmitting surface immediately abovethe upper extremity of the burner flame, thereby insuring rapid heattransfer and yet avoiding spasmodic steam gen- 5 eration.

Another object is to devise a water heating apparatus having acombustion chamber unit surmounted by` a separate storage unit, thestorage unit having a heat absorbing surface 10 over which ue gasesissuing from the combustion chamber are adapted to pass.

It is still another object of my invention to devise a novel liquid fuelburning device particularly adapted for use with water heating ap- 15paratus.

Further objects of the present invention will lbecome apparent, as thedescription thereof proceeds in connection with annexed drawings, andfrom the appended claims.

In the drawings:

Figure 1 is a vertical sectional view of a liquid fuel burning apparatusforming part of my invention and in the present instance it takes theform of a 'hot water heater, and the ignition 25 means and relatedaccessories have not been shown as they form no part of the presentinvention.

Figure 2 is a fragmental sectional View of the flame ring assemblyutilized in the heater shown 30 in Figure 1, and illustrates the methodof securing it to the hearth.

Figure 3 is a perspective View of one of the brackets employed to holdthe flame ring assembly in place.

35 Figure 4 is a fragmental sectional view of the flame ring and grillassembly of the mechanism shown in Figure 1, and illustrates the detailsof its construction.

Figure 5 is a vertical sectional view of a liquid 40 fuel burningapparatus of slightly modified construction, also forming part of thepresent invention.

Figure 6 is a sectional view taken on the line 6-6 of Figure 5.

Figure '7 is a vertical sectional view of a further modii-led form ofliquid fuel burning apparavtus forming part of my invention, and

Figures 8, 9, l0, 11 and 12 are fragmental sectional views illustratingthe configuration of 50 one of the Water cells shown in Figure 7, and

they are taken on the corresponding section lines of that figure.

Referring now to the drawings, wherein like reference characters havebeen employed to des- 55 ignate like parts throughout the several Viewsthereof, the device generally consists of a base section A, whichsupports a boiler or combustion chamber section B; a burner C; and a hotwater storage section D.

Base A comprises an annular member I having an inwardly extendingportion providing an annularseat I I. The inwardly extending portion ofbase member I 0 is reinforced by a plurality of triangular reinforcingwebs I2. Boiler 65 B comprises a generally cylindrical, doublewalledbody I3 having Aan inwardly extending lower portion I4 which not onlysupports the fuel burning apparatus but also constitutes the hearth ofthe furnace. Portion I4 of the boiler 70 defines a vertically extendingcylindrical passage I through which the burner mechanism extends, aswill be hereinafter explained. Boiler section I3 rests upon .seat II ofbase I Il and issecured thereto. `Any suitable securing means 5 may beutilized but I preferably provide member I3 with a plurality of lugs I6through which bolts I'I extend and cooperate with nuts I8 to hold theparts in assembled relationship, y The inner cylindrical wall of memberI3 is provided With a plurality of preferably radially .inwardlyextending fins 2|, which operate to greatly accelerate the transfer ofheat from the combustion chamber into the water contained in the boiler..Fins 2I preferably extend from a region near the top of the boilerdownwardly to a predetermined distance from the bottom of the boiler fora purpose that will presently be set forth. Fins 2|, intermediate theirends are each provided preferably with at least one notch 22 for thepurpose of avoiding the development of severe internal stresses therein,due to the temperature gradient present throughout the longitudinaldimensions of the lns when the apparatus is in operation. Heat enteringeach n 2| is conducted radially outward towards the wall I9 throughwhich it is released to the water, and in order to increase the rate oftransfer from fins 2| to wall I9 they are preferably integrally formedtherewith, when the boiler is cast.

It has been found that unless a large volume of conducting material isprovided, heat ow will be restricted, the tips of the ns overheated andtheir general effectiveness quently, the proper form of the fin sectionis important and in general each fin 2I will be of gradually increasingthickness towards its base.

reduced. Conse- The number of fins used in the boiler will vary with therequirements of the particular installa-- tion, such as the combustionrate, and in most cases they will be present in greater numbers thanthat shown in the drawings, which have been reduced in number in orderto simplify the disclosure.

- Boiler section I3 is provided with an inspection opening of ysuitablesize which is closed by a door 23. Secured to door 23 in any suitablemanner, is a plate 24 and a channel member 25 having a body ofinsulating material 26 disposed therebetween so as to minimize heat lossfrom the furnace in this region. If it is desired to inspect or servicethe burner or boiler, door 23 may be opened to give access to theseparts.

Storage section D of the boiler is preferably constructed of pressedsteel, and consists of a cylindrical part 32 which is preferably thoughnot necessarily of the same diameter as the outer diameter of boiler B.Secured to the lower end of member 32, as by welding or a likeoperation, are a plurality of lug members 33. A plurality of lugs 34 arecast on the upper end of boiler B in alignment with the lugs on section32, and a plurality of bolts 35 and nuts 36 cooperate with lugs 33 and34 to hold the storage section in place on top of the boiler.

A lower head 31 having a central aperture'is welded in place withinmember 32. An upper head 38, having a central aperture therein, issecured to the upper end of section 32, as by a welding or likeoperation, and a central cylindrical member 39 extends through theapertures in members 3'I and 38, and is welded in place in Lower head 3lis provided with a pair of del pressed portions 4I, only one of which isshown. An aperture is provided in each o1' the depressed portions 4I,which align with apertures formed in the upper surface of boiler sectionI3, and a coupler member 42 extends therethrough, in order to establishfluid communication between the boiler and storage sections.

Central member 39 extends upwardly beyond the storage tank proper, andsecured thereto by means of bolt and nut assemblies 43, is a flue member44 having a horizontal portion 45 which is adapted to be connected to aflue gas exhaust pipe in any suitable known manner.

The entire device, including the sides and top of the boiler and storageunits, are covered with any suitable form of insulating materialdesignated generally at 48, in which are provided suitable recesses 49to accommodate the various lug and bolt assemblies. The insulatingmaterial is then preferably covered by a sheet steel cylindrical memberI, and a flanged cover 52.

Although other types of burners or fuel burning devices may be employedwith the boiler and storage construction just described, I preferablyemploy a burner of the wall iiame type as it is this type of burner,with combustion initiated at the periphery of the hearth, and completedin close proximity to the boiler wall, which is suited for my purposeand renders the entire assembly capable of proper and extremely ecientoperation.

The lower and upper inlet and outlet connections respectively for theheated water, irrespective of whether the apparatus employed as a hotwater heateror a boiler are connected to the boiler and storage chamberin any wellknown manner and they have accordingly been omitted from thedrawings.

The burner mechanism proper, designated as C, forms no part of thepresent invention as it is fully shown and claimed in my co-pendingapplication Serial Number 729,928, filed June 9, 1934, and it willaccordingly be only briefly described. Burner C is provided with acylindrical portion which extends through aperture I5 in member I4 andis preferably secured in place therein by means of a plurality of capscrews 54, which are threaded into an enlarged boss on the inner portionof water leg I4.

The fuel and air supplying mechanism broadly consists of a motor 55,having a rotatable head 56 driven thereby. Head 56 comprises a pluralityof fan blades 5'I and a plurality of slightly upwardly inclined fueldelivering nozzles 58.

Oil, in the form of unatomized droplets, is projected outwardly fromhead 56 toward a flame ring assembly comprising an annular ring 62 and ahigher carbureting. ring 63. Rings 62 and 63 are positioned on the uppersurface of fportion I4 of the boiler by means of bosses 6I and aresecured in place thereon by means of brackets 64, spaced at intervalsaround the periphery of rings 62 and 63 and secured to bosses 6I bymeans of screws 65 or the like.

Disposed on top of ring 63 is a grill assembly which preferably consistsof a plurality of plate members 66 having inner and outer flanges 61 and68, respectively. Grill members 66 are secured togetxher in any suitablemanner, (not shown)'/to form an annular grill, and they are providedwith upturned Vanes 69, which serve to cooperate with the air currentsand establish a partial vacuum on the upper sides of members 66, in amanner to be presently set forth. The grill assembly is preferablysecured to member 63 by means lof a plurality of angle members 'II whichare welded or otherwise suitably fastened to the grill members and toring 63.

into the water contained in the storage tank The operation of myconstruction will now be described. The burner motor is started and thefuel is ignited in any well-known manner, and when steady combustionconditions are obtained, the conditions illustrated in Figure 1 exist.With reference to Figure 1, the oil is projected outwardly and slightlyupwardly from head 56 as represented by the upper rows of arrows. Theoil is preferably in a substantially unatomized state, and, therefore,the droplets do not ignite or atomize as they are passing from head 56to ring 63. However, as the" drops strike ring 63, the impact causesthem to be broken up into ne particles, and this action, when coupledwith the high temperature of ring 63, establishes a region of nelydivided fuel, adjacent ring 63, which is swept over and is mixed withair currents passing outwardly from head 56 as indicated by the lowerrows of arrows, and which is suii'cient to estab- `lish an eiiicientlycombustible mixture. The fuel mixture burns to some extent below thegrill, but for the most part it passes upwardly through the openings inthe grill assembly and burns above the grill.

As previously stated some combustion takes place below the grill, butmost of it is confined to the upper side thereof, where intensely hottemperatures are produced, the fuel burning with a blue flame adjacentwall I9, with the result that a. large part of the heat developed israpidly conducted to the water in and adjacent to this region. As isseen in Figure 1, the visible portion of the wall flame terminatesadjacent-the lower ends of fins 2|, and it is highly desirable that thiscondition of combustion be maintained at all times, for the reason thatif the fins extended downwardly through the visible flame region, carbonwould not only collect `thereon, but spotty flame conditions would beestablished, and moreover, dangerous temperatures would be set up in thefins, and they would undoubtedly be seriously burned.

The hot gases of combustion, after leaving the visible flame zone, passupwardly in surface engagement withns 2|, to whichA they communicate thegreater part of their heat, thereby rapidly conducting heat to the watercontained in the boiler. After leaving the boiler space, in

view of the ecient heat removing capabilities of the latter, thecombustion gases have lost the greater part of their heat. They thenpass upwardly in contact with lower head 31 of the storage space, andthen into the cylindrical central member 39 of the storage space, wheretheir upward travel is retarded by baille 40, with the result that thegreater part of the remainder-of the utilizable heat of the flue gasesis transmitted thereby keeping it up to the desired temperature. Theiiue gases then pass outwardly through conduit 45 into the stack in awell-known manner.

It is therefore observed that the major portion of the heat generated bythe burner is transmitted from the combustion chamber itself into thewater, rather than depending upon extended flue passages beyond thecombustion chamber to conduct the heat into water.

It should be particularly observed that as the' hearth of this boilerconstitutes a water-backed.

.head 56.

deflection of the air currents emanating from This is desirable aspreviously explained, because separating the oil currents from the aircurrents tends to prevent initiation of combustion until the fuelactually impinges against ring 63, where it is desired that combustiontake place.

The employment of the wall flame burner in the present boiler, resultsin a practical, leakproof and air-tight combination. rIfhis is indistinct contrast with the .refractory flame hearth, and refractoryflame segments, which have been heretofore used in boilers and whichabsorb oil and frequently leak, and which in time crack, and allowentrance of excess air which would naturally result in impropercombustion condition.

With reference now to Figures 5 and 6 of the drawings, I haveillustrated a modified form of combustion chamber also having a slightlymodi-- fied form of amering mounted therein. As many of the parts ofthis device are identical in structure and function to correspondingparts of the apparatus just described, certain parts have been omitted,and other parts have been given like reference characters.

With continued reference to Figures 5 and 6, burner C extends throughand is secured to a metal plate 80 which is secured to a downwardlyfacing annular seat 8| formed on boiler |3a, by means of a plurality ofcap screws 82. Plate 80 also functions to support the flame and grillrings and to this end a plurality of bracket members 84 are secured tothe upper side thereof by means of screws 83. A hearth plate 85, whichsnugly embraces the stationary part of the burner head, rests upon theupper ends of bracket 84 and is secured thereto as` by means of a tackwelding or like operation. Secured to the upper side of hearth plate 85,are a ring 86 and a carbureting Yring 81, the latter being lU-shaped incross section. Rings 86 and 81 function in the same manner as the flamerings of the apparatus just described, and secured to the outer flangeof ring 81 is a grill 88 having varies 89 struck out of the bodythereof.

In this form of the invention, the upper end yof the boiler is broughtinwardly to provide an upper water leg 13, having a generallycylindrical opening 14 at its center. This increases the heat absorbingarea of the upper portion of the combustion chamber, and in order toincrease the rate of heat transferred into the water, the lower sidethereof is provided with fins15. Opening 14 is provided with fins 16,and the upper side of the water leg is provided with fins 11. Disposedabove opening 14, and resting upon the boiler, is a baille member 18which is employed to cause the hot flue gases to flow outwardly and thenover the lower surface of storage tank 31, to increase the heat transferand thereby prevent the ue gases from escaping directly into the stack.

It is observed that ns 15, 16, and 11 are not continuous but terminateadjacent their joinder with the walls of the boiler. 'I'his isdone inorder to prevent the fins from burning. If the fins were continuous themetal of the ns adjacent the bends in the boiler wall would be compelledto i'mpose all of the heat transmitted thereto upon the corners oftheupperwater leg 13, and it has been found that such corners should not becalled upon to, and are incapable of dissipating the high temperaturesto which a fin of this character is subjected in a boiler.

This device functions in very much the same manner as the apparatus justdescribed. When the burner is operating, the oil and air emanating fromhead 56 take the paths indicated in Figure 5, and it is seen that thevisible flame terminates adjacent the lowermost extremity of fins 2|, asin the previously described apparatus. In this construction, however,the hot gases of combustion, after passing upwardly along fins 2|, andover the vertical face |9 of base |3a, then pass inwardly over a lowersurface of leg 13,-and in contact with fins 15, thence through aperture14 in contact with ns 16. After the flue gases pass through aperture 14,the greater part of their heat has been abstracted, but they are thendirected outwardly by baffle 18 into contact with fins 11, where furtherheat is abstracted therefrom. The flue gases then pass inwardly incontact with head 31 of the storage tank, and thence upwardly throughthe storage tank as described in connection with the first form of myinvention.

With reference to Figures 7 to 12 of the drawings, I have illustrated afurther modification of my invention, and the major change thereinresides in the modified form of the combustion chamber utilized and themodied nature of the heat transmitting surfaces. In this form of theinvention, the burner construction is the same as that utilized in theapparatus shown in Figures 5 and 6, and the lower end of the boiler issimilar in form. Accordingly, similar reference characters havebeen'applied to these parts.

The inner wall of boiler |3b` extends upwardly above the flame ring 'andhas a cylindrical configuration as illustratedin Figure 12, and it thenbranches inwardly in the form of a plurality of hollow ns or water cells9|, which are preferably substantially radially disposed.

Cells 9| are observed to present considerable area to the furnace gases,and as they terminate ush with the flue gas exhaust passage 92, of thecombustion chamber, they do not impede proper gas iiow from thecombustion chamber.

It is moreover observed that cells 9| extend down- Y wardly andpreferably terminate substantially the same distance from the flame asthe fins employed in the previously described forms of my invention. Ifdesired however, the cells in this form of the invention may be allowedto extend further downwardly for. the reason that they are of uniformthickness and are backed by a body of water and there is accordingly nodanger of burning them. This provides a large area of exposedheat-absorbing area in the region of the hottest part of the flame,and/heat transfer in the apparatus is accordingly` extremely rapid. Thisboiler provides a large area of water contact and thereby reducesthe-amount of heat to be absorbed per unit area, and thereby eliminatesthe likelihood of a blanketing layer of steam forming at a highly heatedsurface, which would not only reduce the speed of heat transfer, butwould also undesirably agitate the water because of the spasmodic natureof the steam generated thereby. The large body of water with smoothpassageways provided for the easy and orderly flow of convectioncurrent, makes the boiler extremely efcient in operation.

It is to be observed that in all of the forms of the inventiondisclosed, the amount of heat transferred from the combustion chamberitself is tremendously increased over that of boilers .heretoforeproposed, with the result that it is sages beyond the combustion chamberfor transferring the heat generated by the burner to the water or othermedium. It is moreover seen that the particular type of burner utilizedin the various forms of my invention forms an essential part of thecombination, for the reason that it produces a flame that is in thenature of a wall, located in close proximity to the surfaces to beheated, with the result that the flame zone is not only placed in theproper position for most ecient operation of the unit, but also, as theflue gases naturally flow upwardly in contact with the fins and upperwalls of the combustion chamber, they too are utilized to the bestadvantage. Further economies of operation resulting from the use of thewall type burner reside in the fact that the metal parts of the burnerassembly reached their relatively high operating temperatures quicklyand maintained their high temperatures during operation with resultinghigh cornbustion efficiency. In addition to the amount of heattransferred to the exposed heat absorbing areas by direct radiation fromthe flame, there is a marked amount of energy radiated from heatedportions of the hearth (Figures 5 to 12), as the highly heated metalportions are maintained at a visible color heat during operation, andbeing largely surrounded by an absorbing heat surface, most of thisradiant heat energy is effectively transferred.

It is to be understood that although I haveV illustrated a boiler 'andstorage assembly having a cylindrical configuration, if desired anassembly of rectangular section having a flame ring assembly of similarshape may be employed without departing from the spirit of the presentinvention. It is to be moreover understood that the term boiler, as usedin the present specithe meaning and range of equivalency of the claimsare therefore intended to be embraced therein.

What is claimed and desired to be secured by United States LettersPatent is:

1. In a fuel burning apparatus, an upright boiler unit providing asubstantially vertically extending combustion chamber, a centrallydisposed liquid fuel burning device located adjacent the lower end ofsaid combustion chamber for causing a flame to impinge on the sides ofsaid chamber, and a substantially horizontally disposed watercooledhearth disposed ,between said fuel burning device and the sides of saidcombustion chamber, said fuel burning means comprising a flame ringseating upon the peripheral portion of said substantially horizontallydisposed waterbacked surface and adjacent which combustion is adapted totake place.

2. The apparatus described in claim 1, wherein said liquid fuel burningdevice comprises a liquid fuel distributing device which is operable toproject a layer of liquid fuel and a layer of air outwardly toward thesides of said combustion chamber in substantially segregated condition,and wherein said water-cooled hearth is operable to assist insegregating said fuel and air, in its travel from said fuel distributingdevice to said flame ring.

3. In a fuel burning apparatus, a substantially cylindrical uprightboiler unit having hollow heatconducting walls defining a combustionchamber, said boiler unit at the lower end thereof having ahollow-Walled portion which extends inwardly and defines the floor ofthe combustion chamber and which is disposed in fluid communication withsaid first named hollow walls, and fuel .burning means disposed in saidcombustion chamber and operable to impart heat to said hollow walls andalso to said hollow-walled portion of said boiler unit, said fuelburning means comprising a flame ring seating upon the peripheralportion of-said substantially horizontally disposed water backed surfaceadjacent which combustion is adapted to take place, said hollow- Walledportion of said boiler unit having a substantially centrally locatedaperture therein, and a liquid fuel and air proiecting mechanismextending through the aperture in said hollow Walled yportion of saidboiler unit.

MILTON A. POWERS.

